Carton construction



Aug. 29, 1961 F. P. ZILLES CARTON CONSTRUCTION Filed Oct. e, 1958 ATTORNEYS.

United This invention relates to an improved carton construction for packaging granular material such as soap, detergents, sugar and the like. Cartons of this kind are made in various sizes to package desired quantities of bulk material.

The primary difiiculty in connection with cartons made heretofore is the distension or bulging of the relatively wide front and rear panels, particularly when the bulk material is dense. The distortion resulting from these bowed out panels makes the carton difiicult to package for shipment and to stack on the display shelf. Moreover, the carton is unattractive as compared with one having erect parallel faces and it appears to be only partly filled when opened by the customer because the contents pack down as the carton distorts. Occasionally, manufacturers find it necessary to fill the carton with more than the desired amount of material to compensate for the lower level.

It has been proposed to solve this problem by increasing the caliper of the board from which the carton is prepared, or by using a higher quality, long fiber board. Both of these solutions entail a considerable increase in the cost of the carton. In view of the astronomical quantities of cartons of this type used in packaging bulk goods, only a minute increase in the cost means that the manufacturer must spend vast sums of money for the improved carton.

It is the object of this invention to provide a carton construction which can be made from relatively lightweight, inexpensive fiber board, which does not bulge out when filled with dense bulk materials and which may be made on conventional equipment,

In a preferred form of the invention the carton is made from a single, unitary blank which, when set up, has a central rib or bulkhead tying the opposed front and rear panels of the carton together to prevent the aforesaid undesirable bulging.

Other objects of this invention will become apparent from the description which follows when read in conjunction with the accompanying drawing, wherein:

FIGURE 1 is a perspective view of the carton of the invention in fully assembled condition;

FIGURE 2 is a view similar to FIGURE 1 in which the carton is partially collapsed;

FIGURE 3 is a cross-sectional view taken along the line 3-3 of FIGURE 1; and

FIGURE 4 is a developed plan view of the unitary blank from which the carton is assembled.

The cartons of the invention are generally slab-shaped and comprise four rectangular panels or side walls closed in at the ends by means of flaps, which comprise extensions of the side walls. The front wall and the rear wall 12 are relatively broad as compared with the side walls 14 and 16 which connect the front and rear panels together along fold lines. One end of the blank from which the carton is made terminates in the rib or bulkhead 18 which extends from the rear to the front panel. The rib 18 has a flange 20 which is glued to the inside of the front panel. The other end of the blank 26 overlaps the first end adjacent the fold line 19, as best shown in FIGURE 3. The overlapping portion is designated by the numeral 26 and is glued securely to the face of the rear panel 12.

Referring to the plan view of the blank shown in FIGURE 4, the fold lines are designated by broken or dotted lines. The flaps 40 and 42 are located at either end of the box and serve to enclose the top and bottom adjacent the sides 14 and 16. The flaps 38 are folded at the top and bottom and comprise part of the front panel 10. Since the rear panel contains a seam, it is desirable that the flap forming an extension thereof be modified so that there is not a double thickness of material where the fold occurs. Consequently, the end 26 is cut out at the top and bottom edges to provide triangular projections 31 which comprise part of the flaps 30 and 32. Likewise, the other end of the blank is cut out adjacent the rib 18 to provide the angular portions 33 comprising part of the flaps 30 and 32. By means of this construction there is no double thickness of material along the fold line since the tab 26 terminates just short of the fold line. By cutting the flaps 30 and 32 angularly as indicated, the triangular portions 31 and 33 overlap so that there is no gap where the two ends of the blank came together. The area of the overlap is triangular in shape and increases in width from the fold line out to the edge of the flap. In other words, the triangular-shaped overlap has its apex coincident with the fold line. This is an important feature of the present invention.

The bulkhead 18 terminates in a flange 20 which carries a coating of glue 24 for securing the flange tothe front panel. A plurality of openings 22 may be cut through the bulkhead 18 in order to permit flowable solid material to pass from one section of the carton to the other.

By means of the present construction it is possible to utilize cardboard which is considerably lighter than that which would be required to prevent bulging of the front and rear panels without the bulkhead. The additional paper involved in forming the bulkhead and the cost of gluing it to the front panel are considerably less than the increased cost of long fiber stock or higher caliper Stock. It will be appreciated that the carton of the invention is very simple in construction and can be produced on stand ard carton manufacturing equipment. The top and bottom may be closed in the conventional manner by folding down the flaps '38, 40, 42, 30 and 32 extending from either end thereof. After the seam extending longitudinally of the rear panel has been made and the bulkhead has been glued to the front panel, the partially assembled carton can then be stored in the flat until it is fed into the packaging machine.

Although a preferred form of the invention has been shown in the drawing and described herein, it will be understood that various modifications may be made in the construction of the carton without departing from the true scope and spirit of the invention. It is, therefore, my intention to cov r any equivalents or modifications which may reasonably be included within the scope of the appended claims. V

What I claim as new and desire to secure by Letters Patent of the United States is:

A carton for dense bulk material made from a unitary,

Patented Aug. 29, 1961 lightweight, single-ply paper board blank comprising broad front and rear rectangular panels connected by relatively narrow side panels, said panels having end flaps to close the top and bottom of said carton, a bulkhead containing openings extending between said front and rear panels and adhesively secured to said front panel to tie said panels together, and a seam in said rear panel formed by one end of said blank overlapping the other end along a line spaced inwardly from said other end, the marginal portion of said other end extending beyond said seam and constituting said bulkhead, and the end closure flaps projecting from said rear panel on either side of said seam overlapping in an area triangular in shape with the apex of the triangle coinciding with the fold of the flap.

References Cited in the file of this patent UNITED STATES PATENTS 1,815,565 Hill et al July 21, 1931 2,154,085 Bergstein Apr. 11, 1939 2,239,442 Gredell Apr.'22, 1941 2,239,507 Pierce Apr. 22, 1941 2,412,666 Zinn Dec. 17, 1946 

